Pololu A-Star 32U4 Mini Series Manual

Overview
The Pololu A-Star 32U4 Mini boards are general-purpose programmable modules based on
Atmel's ATmega32U4 AVR microcontroller, which has 32 KB of flash program memory, 2.5 KB of
RAM, and built-in USB functionality. The A-Star (areviated A*) adds a number of onboard features
to support the microcontroller and make it easier to work with, including a 16 MHz crystal, a USB
Micro-B connector, an in-system programming (ISP) header, a reset button, and three indicator
LEDs.
Each A-Star 32U4 Mini contains a switching regulator that efficiently produces 5 V from an external
voltage source to power the microcontroller. Three different versions are available, covering a wide
range of input voltages:
A-Star 32U4 Mini ULV: 0.5 V to 5.5 V
A-Star 32U4 Mini LV: 2.7 V to 11.8 V
A-Star 32U4 Mini SV: 5 V to 36 V
A robust power selection circuit enables seamless transitions between regulator power and USB
power, and overcurrent and reverse-voltage protection help safeguard the board against accidental
damage.
All 26 general-purpose I/O lines on the ATmega32U4 are accessible on the A* 32U4 Mini; 7 of
these are usable as PWM outputs and 12 are usable as analog inputs. The board measures
1.9" × 0.7", the same size as an Arduino Micro, and features a pair of mounting holes sized for #2
or M2 screws (not included). Its 0.1" pin spacing makes the A* easy to use with solderless
breadboards, perfboards, and 0.1"-pitch connectors.
Our comprehensive user's guide provides the basics you need to get started with the A-Star as
well as detailed technical information for advanced users.
This product requires a USB A to Micro-B cable (not included) to connect to a
computer.
Features
Dimensions: 1.9" × 0.7" (1.95" × 0.7" including USB Micro-B connector)
A-Star 32U4 Mini LV
A-Star 32U4 Mini ULV, LV, and SV.